The present invention relates, among other things, to a device for providing indications of deviations of an inner wall of a pipeline from a nominal cross-sectional configuration. However, the device may be utilized to sense any location-specific property of the pipeline as the profiler or other sensor(s) passes through the pipeline.
Internal calipering of buried pipeline or of offshore pipeline is desirable for several reasons, e.g., to locate and repair damaged or obstructed sections of a pipeline which might be hazardous to safe operation. Thus, a pipeline may be damaged as it is laid, especially during the back fill operation, so that it may have serious dents, out of round sections, etc. Damaged areas of the pipeline can cause a flow restriction which in some cases will stop or damage standard pigs or the damaged areas may cause stress concentration points susceptible to failure. Inspection of this type is also desirable to locate areas damaged during line operation. Pipelines at river crossings or other underwater locations are especially subject to such damage.
The provision of a mechanism to internally caliper a pipeline presents several problems, depending upon the environment involved. Thus, the mechanism should be capable of continuously traversing long lengths of line without excessive wear which would either cause it to fail or to give erroneous indications of the internal configuration of the pipeline. It should also give full coverage of the inner wall of the pipeline; it should be able to pass through curved portions of the pipeline without indicating departures from such normal configuration; and it should be able to pass side openings, valves, etc. without being damaged.
Accordingly, it is a primary purpose of this invention to provide a mechanism which solves these problems and which can be propelled along the pipeline by fluid flowing through the pipeline so that the mechanism is a self-contained unit, capable of calipering over great distances and detecting deviations in inner pipe wall configurations as they may occur from place to place along the pipeline and capable also of sensing other location-specific properties of the pipeline, if desired.
Other purposes, advantages and features of the invention will be apparent to one skilled in the art upon review of the following.
Applicant is not aware of any prior art references which, in his judgment as one skilled in the pipeline art, would anticipate or render obvious the novel pipeline sensor of the instant invention; however, for the purposes of fully developing the background of the invention and establishing the state of the requisite art, the following references are set forth: U.S. Pat. Nos. 3,755,908; 3,685,158 and 4,243,099.